This type of a shell structure has several applications, in civilian application as underground cellars, public shelters, storages, and the like. In military application, such shell structures can be used as dugouts.
For example, U.S. Pat. No. 3,968,603 describes prefabricated metal buildings consisting of a plurality of individual U-shaped building elements, which are connected with each other, and the like, by means of clamps or other suitable fasteners. Reinforcing web structures are necessary to stabilize the buildings. Erecting such buildings requires specific tools, is time consuming and requires considerable labor. Due to their enormous weight, these structures cannot be moved from one place to another as a whole. These structures must be dismantled for this purpose, which again requires specific tools, and is time and labor consuming.